• 한국환경과학회지
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• 제21권10호
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• pp.1255-1263
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• 2012

Batch cultivations were performed to evaluate the influences of the initial pH condition on mesophilic and thermophilic acidogenic fermentation with food waste recycling wastewater. In both conditions of mesophilic and thermophilic fermentation, TVFAs production rates were maximized at the initial pH 7 condition as 0.15 and 0.23 g TVFAs/L hr, respectively. And pH was also maintained stably between 6 and 7 during 72hr acidogenic cultivation at both conditions. However, predominant VFA components were different according to reaction temperature conditions. In mesophilic condition, propionic acid which has low conversion efficiency to methane was accumulated up to 1,348 mg/L while acetic and butyric acid were predominant in thermophilic condition. Therefore, thermophilic acidogenic fermentation was superior for the effective VFAs production than mesophilic condition. From the DGGE analysis, the band patterns were different according to the initial pH conditions but the correlations of the each band were increased in similar pH conditions. These results mean that microbial communities were certainly affected by the initial pH condition. Consequently, the adjustment of the initial pH to neutral region and thermophilic operation are needed to enhance acidogenic fermentation of food waste recycling wastewater.

• 한국환경과학회지
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• 제15권10호
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• pp.975-982
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• 2006

This study has been conducted to optimum operating conditions for effective acid fermentation according to OLR(organic loading rate) in the mesophilic and thermophilic acid fermentation process. The results are summarized as follows. In order to obtain reasonable acid fermentation efficiency in performing acid fermentation of food wastes in thermophilic condition, organic loading rate was required below 20 gVS/L.d. As $SCOD_{Cr}/TKN,\;SCOD_{Cr}/T-P$ of thermophilic acid fermented food wastes In organic loading rate 20 gVS/L.d were 18.9, 73.4 respectively, it was possible to utilize as external carbon source for denitrification in sewage treatment plant after solid-liquid separation as well as co-digestion of fermented food wastes and sewage sludge.

• 상하수도학회지
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• 제21권4호
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• pp.467-475
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• 2007

This study was conducted to examine temperature effects on hydrogen production in anaerobic fermentation. 18 batch reactors were operated at mesophilic ($35^{\circ}C$) and thermophilic conditions ($55^{\circ}C$) to achieve maximum hydrogen production in anaerobic fermentation. Optimum hydrogen production conditions were also investigated at each temperature. Different trends were observed regarding pH effects on hydrogen production. This effect was not significant for mesophilic fermentation ($35^{\circ}C$). In this case, pH may not drop to interfere hydrogen production during the test. However, hydrogen production decreased without pH control for thermophilic condition ($55^{\circ}C$). Effects of heat treatment were observed for both fermentation process. Hydrogen production with heat treatment was higher than hydrogen production without heat treatment for both fermentation processes. The amount of produced hydrogen for each substrate concentration with temperature changes showed that more hydrogen was produced at $35^{\circ}C$ than at $55^{\circ}C$.

• Journal of Microbiology
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• 제44권3호
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• pp.276-283
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• 2006

The thermophilic fungus Thermoascus aurantiacus 179-5 produced large quantities of a glucosidase which preferentially hydrolyzed maltose over starch. Enzyme production was high in submerged fermentation, with a maximal activity of 30 U/ml after 336 h of fermentation. In solid-state fermentation, the activity of the enzyme was 22 U/ml at 144 h in medium containing wheat bran and 5.8 U/ml at 48 h when cassava pulp was used as the culture medium. The enzyme was specific for maltose, very slowly hydrolyzed starch, dextrins (2-7G) and the synthetic substrate (${\alpha}$-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II ${\alpha}$-glucosidase. The optimum temperature of the enzyme was $70^{\circ}C$. In addition, the enzyme was highly thermostable (100% stability for 10 h at $60^{\circ}C$ and a half-life of 15 min at $80^{\circ}C$), and stable within a wide pH range.

• Journal of the Korean Wood Science and Technology
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• 제34권1호
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• pp.68-78
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• 2006

돈분뇨 분해 장치의 발효 속도를 가속화시키는 토착미생물의 확보를 위하여 우리나라 각 지역에서 수집한 균주 중 우수한 균주를 선별하고 168 rDNA 증폭에 의한 동정을 실시하여 돈분뇨 분해에 관여하는 균주의 특성을 확인하기 위해 본 연구에서는 총 23장소(서울, 충청, 강원, 전북, 전념, 경남 지역)에서 28종류의 부숙 퇴비를 수집하여 생균수를 조사한 결과 대체적으로 $1{\times}10^5{\sim}10^8$의 분포 밀도를 보였다. 분리한 균주의 효소 생산 역가결과는 $30^{\circ}C$에서 보다 $55^{\circ}C$에서 배양된 고온호기성박테리아가 상대적으로 높은 섬유소분해효소와 전분분해효소 생산력을 보였고, genomic DNA의 추출에 의한 168 primer로 증폭하여 염기서열을 결정한 결과 돈분뇨 발효에 관여하는 고온호기성박테리아는 15종으로 동정되었다. 그 중 미생물제재를 제조하기 위하여 효소 역가 면에서도 우수성을 보이고 내생 포자를 형성하는 균주는 Bacillus subtihs로 확인되었다.

• 유기물자원화
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• 제16권2호
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• pp.29-37
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• 2008

본 연구에서는 하수슬러지, 음식물쓰레기, 분뇨계 폐기물과 같은 고농도 유기성 폐기물의 고온 메탄 발효에 대하여 공정, 응용 현황 및 장 단점의 여러가지 측면에서 고찰이 이루어졌다. 고온 메탄 발효의 장점은 반응속도가 빠르고, 높은 부하량에서 처리가능하고, 병원성 미생물의 사멸율이 높고, 소화오니는 보다 위생적이었다. 그러나, 단점으로서는 발효시설을 가열하는데 많은 에너지를 요구하고, 저농도 유기성 폐기물에서는 잉여에너지를 얻을 수 없고, 발효처리 후 상등수 수질이 떨어지게 되며, 그 결과 배수처리에 부담이 된다. 특히, 고농도 메탄 발효의 경우 영양염 부족이나 ${NH_4}^+-N$에 의한 방해가 일어나기 쉬우므로, 이에 대하여 적절한 대안이 요구된다. 일반적으로 고온 메탄 발효는 고농도의 우분뇨와 음식물 유기성 폐기물의 좋은 처리 수단으로 고려되었다. 반대로, 폐기물 그 자체의 농도가 낮을 경우와 ${NH_4}^+-N$이 3.000mg/L 이상 높게 되는 조건에서 고온 메탄 발효는 바람직하지 않는 결과를 나타내게 된다.

• 한국물환경학회지
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• 제21권1호
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• pp.34-39
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• 2005

The performance of elutriated acid fermentation with slurry-type piggery waste was investigated, especially to evaluate the effects of temperature and pre-treatment. In the first phase, the acid elutriation reactor with piggery waste after centrifugation operated at both mesophilic and thermophilic conditions to evaluate the effect of temperature. Solubilization yield($gVFAs/gSCOD_{prod.}$) and acidification rate($gVFAs/gSCOD_{prod.}$) in the thermophilic digestion were 0.45 and 0.55, which were higher than those of the mesophilic digestion, 0.25 and 0.45. In addition, the acid elutriation reactor at thermophilic temperature is more effective in removing e-coli. In the second phase, the acid elutriation reactor was fed with piggery waste before centrifugation. With piggery wastes before centrifugation, the solubilization yield and the acidificaton rate were 0.40 and 0.80, respectively, which were higher than the rates using piggery waste after centrifugation at both mesophilic and thermophilic conditions. The higher sludge volume reduction of 80% benefits sludge management. Furthermore, economical advantages can be achieved by removing the pre-treatment process, such as centrifugation. Consequently, the treatment with piggery waste before centrifugation proved to be effective. Also, the optimum temperature condition was estimated at mesophilic or thermophilic conditions, considering solubilization yields and acidification rates, though the system should be heated.

• Applied Biological Chemistry
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• 제27권4호
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• pp.217-224
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• 1984

생전분질원료(生澱粉質原料)를 사용(使用)하는 ethanol발효(醱酵)에 있어서 고온성효모(高溫性酵母)의 사용효과(使用效果)를 시험(試驗)하기 위하여 분리(分離), 보존중(保存中)인 고온성효모(高溫性酵母)(T-71균주(菌株))의 생육온도(生育溫度), ethanol 내성(耐性)등의 특성(特性)을 조사(調査)하고, 몇가지 생전분질원료(生澱粉質原料)를 사용(使用)한 발효시험(醱酵試驗)을 실시(實施)하였다. 고온성효모(高溫性酵母) T-71의 생육(生育) 및 발효최고온도(醱酵最高溫度)는 $42^{\circ}C$이며, 대조균주(對照菌株)보다 $2^{\circ}C$ 이상 높았으며 ethanol함유배지(含有培地)에 효모균체(酵母菌體)를 접종(接種)하여 발효능(醱酵能)을 검토(檢討)한 바 T-71균주(菌株)는 대조균주(對照菌株)보다 ethanol 내성(耐性)이 컸다. T-71균주(菌株)의 발효최적온도(醱酵最適溫度)는 술덧의 종류(種類)와 담금 농도(濃度)에 따라 달라지나 어느 경우나 대조균주(對照菌株)에 비(比)하여 최적발효온도(最適醱酵溫度)가 높았다. 시험균주(試驗菌株)를 각각(各各)의 최적온도(最適溫度)에서 발효(醱酵)시킬 때 고온성효모(高溫性酵母) T-17을 사용(使用)한 경우는 대조균주(對照菌株)의 경우에 비하여 발효기간(醱酵期間)을 $1{\sim}2$일간(日間) 단축(短縮)시킬 수 있었다. 절간생(切干生)고구마술덧에서 T-71균주(菌株)의 최적발효온도(最適醱酵溫度)는 $35{\sim}37^{\circ}C$(생성(生成) ethanol농도(濃度) 9.6% 조건(條件))이며 $40^{\circ}C$에서도 별차이가 없었으나, 보리가루술덧과 절간고구마가루술덧에서 T-71균주(菌株)의 최적발효온도(最適醱酵溫度)는 각각(各各) $35^{\circ}C$(각(各) 생성(生成) ethanol 농도(濃度) 14.0% 및 12.8%조건(條件))이었다.

• 농업과학연구
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• 제11권1호
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• pp.25-33
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• 1984

This experiment carried out to obtain the thermophilic yeast, suitable for ethanol fermentation, and two usable strain were isolated. And microbial characteristics of these strains were investigated, and ethanol fermentation tested. The results obtained were as follows; 1. The selected yeasts were identified D-71 with Saccharomyces cerevisiae, and J-515 with Saccharomyces fermentati. 2. The strains D-71 and J-515 were showed the highest ethanol fermentation activity in the crushed corn mash of high concentration at $35^{\circ}C$, and showed the slightly lower at $40^{\circ}C$ than in the case of $35^{\circ}C$. 3. The strains D-71 and J-515 were showed the very higher ethanol fermentation activity than that of compared strain at $35^{\circ}C$ and $40^{\circ}C$, and at these temperature, fermentation period was a little bit of short. 4. On fermentation test using D-71 and J-515, the residual total sugar in the mash was very lower at $35^{\circ}C$.

• 유기물자원화
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• 제10권3호
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• pp.126-131
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• 2002

남은 음식물을 기질로 생균사료를 생산하기위하여 고온성 세균에 의한 호기적 액체 발효가 시도되었다. 토양이나 남은 음식물들로부터 11종의 고온성 세균이 $55^{\circ}C$에서의 진탕배양에 의해 분리되었다. 이들 분리균 들의 기질분해능을 평가하기위해 배양액 중에서의 ${\alpha}-amylase$ 와 protease효소역가를 측정 비교하였다. 이 결과 6종의 세균이 선택되었고 남은 음식물 기질 적응력을 높이기 위해 반복 배양을 실시하였다. 발효말기에서의 생균농도는 대부분 $3{\sim}7{\times}10^9/ml$에 이르렀다. 이들 중 B3, B6가 가장 높은 효소역가를 나타냈다. B3, B6, 그리고 분양받은 균주인 Bacillus Stearothermophillus를 2L-jar fermenter를 이용해 혼합발효시킨 결과발효개시 8시간 내에 생균수가 $1.4{\times}10^{10}/ml$에 이르렀다.